package com.example.taximeter.config;


import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;


/**
 * 请求拦截器，处理跨域问题
 *
 */
@Component
public class CommonInterceptor implements HandlerInterceptor {

    private List<String> excludedUrls;

         public List<String> getExcludedUrls() {
    return excludedUrls;
  }

          public void setExcludedUrls(List<String> excludedUrls) {
    this.excludedUrls = excludedUrls;
  }

          /**
   *
   * 在业务处理器处理请求之前被调用 如果返回false
   * 从当前的拦截器往回执行所有拦截器的afterCompletion(),
   * 再退出拦截器链, 如果返回true 执行下一个拦截器,
   * 直到所有的拦截器都执行完毕 再执行被拦截的Controller
   * 然后进入拦截器链,
   * 从最后一个拦截器往回执行所有的postHandle()
   * 接着再从最后一个拦截器往回执行所有的afterCompletion()
   *
   * @param request
   *
   * @param response
   */
          public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
      Object handler) throws Exception {
    response.setHeader("Access-Control-Allow-Origin", "*");
    response.setHeader("Access-Control-Allow-Methods", "*");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers",
                        "Origin, X-Requested-With, Content-Type, Accept");
    return true;
  }

          // 在业务处理器处理请求执行完成后,生成视图之前执行的动作
          public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
      ModelAndView modelAndView) throws Exception {

  }

          /**
   *
   * 在DispatcherServlet完全处理完请求后被调用
   * 当有拦截器抛出异常时,
   * 会从当前拦截器往回执行所有的拦截器的afterCompletion()
   *
   * @param request
   *
   * @param response
   *
   * @param handler
   *
   */
          public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
      Object handler, Exception ex) throws Exception {

  }


}
